From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id AFA731F404 for ; Mon, 3 Sep 2018 19:28:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728443AbeICXuA (ORCPT ); Mon, 3 Sep 2018 19:50:00 -0400 Received: from mail-io0-f195.google.com ([209.85.223.195]:34482 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbeICXuA (ORCPT ); Mon, 3 Sep 2018 19:50:00 -0400 Received: by mail-io0-f195.google.com with SMTP id c22-v6so1137336iob.1 for ; Mon, 03 Sep 2018 12:28:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yV7E8qGmJIdz+rzjeMDDTqkvPJHimLuc0jAyausgRlw=; b=ttTdxRphep072jGdypHbxAcHhfHUvZX8AJd+ZYB8YTZOjUgZTmBij+cfkOyVnkLs5n 0gJ922lJNsJC0fj6oKLWKDh+8sORHoHKtpPDW6jeqqexcQ+h8Bl08VPJ/x9CPgiyHDhz 02hscYXvv0UIl3CAjzJ0axMYR0YaNkPnQK4zBTrRZUehkb4Jf493We+fl8tYeOPkGMe0 LGs9h8DZ/6XRDwLEZmhmOXJATo6lBCIWwf8I3mVGpwv7M0DZRxrrlVgPH9WgLcWJLLyk vQhzZuVh43W+xmCdC9YPIc2vrlOkW/n/PUaSFvh/jz3QmoTk1FahWFoVWFnSHMJMFHCP bF4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yV7E8qGmJIdz+rzjeMDDTqkvPJHimLuc0jAyausgRlw=; b=YcPy3iDeMNVFgATLL3+s+AbnqWSONXfBLKRqD597NrACIWMTrzBn3FJam4miglg/Xj 0ub4QsKvValYUm9p7ZOjDrUZ+Bm6LW6zlUNh9LaiC4cBvI4cjpxlrbdQGYBlTNu6RMSR HKwYIrMZizIGDa8KYQvEO4kWjHmPt66lXJsbNOiO73rg/rOissWzx3cLVwde/tEDUs7q NOjCcX5ExVys3sMl7v56uAkgTz9jF6fGBJqI/PxrEdo9rsFNkOZjaJU7XSbSf02OdxkJ wZZdo5ohQXvec5JLFe34lhVP5VEK223zF6jW7XABdApxBEwUJiQ71xq8L6nSGHObFSYT a/CA== X-Gm-Message-State: APzg51CvRSb7QtQxisBq58G1yU8BEaYVgHRRW9UZq5GgtmorpKZS77Eq SX1z2J704Q6TIhwGbdF5de82L6ka2929kOpf5iI= X-Google-Smtp-Source: ANB0Vda2NuTFDoUVJ/ZL45GyC1j56t0T/y3mt9dDf16VCbbocs53g99KLDpXaFwoBYg23LOHvchkOK6wvE2oHEJPKH4= X-Received: by 2002:a6b:8fd0:: with SMTP id r199-v6mr20072734iod.118.1536002903620; Mon, 03 Sep 2018 12:28:23 -0700 (PDT) MIME-Version: 1.0 References: <20180823154053.20212-1-benpeart@microsoft.com> <20180829152500.46640-1-benpeart@microsoft.com> <20180829152500.46640-3-benpeart@microsoft.com> In-Reply-To: From: Duy Nguyen Date: Mon, 3 Sep 2018 21:27:57 +0200 Message-ID: Subject: Re: [PATCH v2 2/3] read-cache: load cache extensions on worker thread To: Ben Peart Cc: Git Mailing List , Junio C Hamano Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Sep 3, 2018 at 9:21 PM Duy Nguyen wrote: > > I used p0002-read-cache.sh to generate some performance data on the > > cumulative impact: > > > > 100,000 entries > > > > Test HEAD~3 HEAD~2 > > --------------------------------------------------------------------------- > > read_cache/discard_cache 1000 times 14.08(0.01+0.10) 9.72(0.03+0.06) -31.0% > > This is misleading (if I read it correctly). 1/3 already drops > execution time down to 9.81, so this patch alone only has about 6% > saving. I may have miscalculated that. 1/3 says -30% saving, here it's -31%, so I guess it's 1% extra saving (or ~3% on 1m entries)? That's definitely not worth doing. -- Duy